Composites based on recycled polypropylene (PP) reinforced with cellulose nanocrystals whit lignin corncob were prepared. The effect of the ratio composites prepared via a compression molding process on the mechanical and thermal properties was analyzed. Corncobs is a little-used agroindustrial residue with a high cellulose content. The corncob was milled and then delignified via the organosolve process in order to get the cellulose unbleached. An acid hydrolysis process was then carried out to obtain lignocellulose nanocrystals (LCNCs). Subsequently, LCNC/PP composites were obtained via termocompression molding using different concentrations of LCNC (0, 0.5, 1 and 2% by weight) previously mixed via extrusion. The residual lignin present in the LCNCs improved the compatibility between the reinforcement and the PP matrix. This was evidenced by the increase in mechanical properties and the stabilization of thermal properties. The results of the mechanical tests showed that the LCNC increases the tensile and flexural modules and strength with respect to neat PP. Composites with 2% of LCNC showed an increase of 36% and 43% in modulus and tensile strength, respectively, while the flexural modulus and strength increased by 7.6%. By using reinforcements of natural and residual origin (corncob) and improving the properties of recycled polymers, their reuse will increase, and this can lead to reducing waste in the environment.

Unbleached cellulose obtained from corncobs was used to synthesize cellulose nanocrystals (CNCs). Corncobs are an agro-industrial residue that has a high cellulose content and can be used as a raw material to obtain CNCs. The cellulose was extracted from the corncobs by means of delignification in two stages. The first stage consisted of a pulping process with ethanol and acetic acid (organosolv method), and in the second stage, the corncob was treated with an organosolv method and potassium hydroxide, followed by sodium hydroxide and boric acid (extraction and purification) to eliminate hemicellulose. The obtained cellulose was not bleached, in order to maintain the groups corresponding to lignin and hemicellulose on their surface. Afterward, the obtained cellulose underwent acid hydrolysis to obtain CNCs, using sulfuric acid at 64%. These nanocrystals were characterized by X-ray diffraction, atomic force microscopy, thermogravimetric analysis and zeta potential. The CNCs obtained from the two types of unbleached cellulose showed lengths from 125.18 to 225.86 nm and diameters from 11.61 to 35.92 nm. The results indicate not only that CNCs can be obtained from unbleached cellulose corncobs but also that their characteristics are similar to those of CNCs obtained by means of bleached cellulose.

This study addresses the urgent need for sustainable alternatives to conventional plastic food packaging by developing and evaluating novel starch-based coatings enriched with chitosan and bacterial nanocellulose (BNC) derived from food waste. These coatings were applied to unripe bananas and their effectiveness in extending shelf-life was assessed over 21 days under controlled conditions. The results demonstrate that the coatings, particularly those containing chitosan, significantly reduced weight loss (up to 35 %), preserved firmness (maintaining 35 % higher firmness), and delayed the increase in reducing sugars (up to 63 % reduction at day 14), effectively doubling the shelf-life of bananas. The superior performance of chitosan-containing coatings is attributed to their film-forming properties, creating a modified atmosphere that retards ripening. This research highlights the potential of valorizing food waste into sustainable, high-performance polymeric coatings for food preservation, contributing to a circular economy in the food industry. Further research is needed to optimize the coatings for long-term effectiveness beyond 14 days.

El rastrojo de la piña está compuesto por el tallo y las hojas, de las últimas se pueden obtener sus fibras, al remover las capas superficiales. Este material usualmente recibe el nombre de PALF (por sus siglas en inglés, Pineapple Leaf Fiber) y su composición química es principalmente celulosa, lignina y hemicelulosa, donde la primera es el componente más aprovechado ya que se encuentra en mayor proporción y muestra propiedades físicas y químicas con distintas aplicaciones industriales. Su utilidad puede ser ampliada y optimizada si a partir de la celulosa se extraen nanoestructuras de mayor valor agregado como lo son los nanocristales de celulosa (CNC) y la celulosa nanofibrilar (CNF).

As water scarcity and pollution increase in rural communities in some parts of developing countries, there is a need to find simple ways to improve the quality of contaminated water. In this research, bagasse-based cellulose membranes were prepared and evaluated in a simple filtration system and compared with polycaprolactone membranes (PCL) and bagasse-based cellulose/PCL membranes for the removal of total coliform bacteria, Escherichia coli and other physical and chemical contaminants from contaminated water. Cellulose offers many opportunities in filtration technology due to its physical and chemical characteristics that allow its use in the design of membranes with flexible capabilities and specific applications. The membranes were characterized physically, chemically and mechanically, finding similarity in mechanical properties and differences in porosity. The membranes were tested in a filtration system and PCL membranes were more effective in removing turbidity (94.5%), color removal (70%) and phosphorus removal (50%), while cellulose membranes were better at retaining fecal coliforms (84.5%) and E. coli (90.8%). Statistical analysis (one-way ANOVA, p < 0.05) confirmed significant differences among the three membrane types for turbidity, apparent color, and nitrate, while no significant differences were observed for pH, conductivity, and phosphorus. These results suggest that the use of the membranes could help to improve the quality of polluted water and more studies are needed in order to improve their efficiencies.